Approximation Trade Offs in an Image-Based Control System
Sayandip De1,a, Sajid Mohamed1,b, Konstantinos Bimpisidis1,c, Dip Goswami1,d, Twan Basten1,2,f and Henk Corporaal1,e
1Electronic Systems Group, Eindhoven University of Technology, The Netherlands
asayandip.de@tue.nl
bs.mohamed@tue.nl
cd.goswami@tue.nl
dh.corporaal@tue.nl
ek.bimpisidis@alumnus.tue.nl
2ESI, TNO, Eindhoven, The Netherlands
fa.a.basten@tue.nl
ABSTRACT
Image-based control (IBC) systems use camera sensor(s) to perceive the environment. The inherent computeheavy nature of image processing causes long processing delay that negatively influences the performance of the IBC systems. Our idea is to reduce the long delay using coarse-grained approximation of the image signal processing pipeline without affecting the functionality and performance of the IBC system. The question is: how is the degree of approximation related to the closed-loop quality-of-control (QoC), memory utilization and energy consumption? We present a software-in-the-loop (SiL) evaluation framework for the above approximation-inthe- loop system. We identify the error resilient stages and the corresponding coarse-grained approximation settings for the IBC system. We perform trade off analysis between the QoC, memory utilisation and energy consumption for varying degrees of coarsegrained approximation. We demonstrate the effectiveness of our approach using a concrete case study of a lane keeping assist system (LKAS). We obtain energy and memory reduction of upto 84% and 29% respectively, for 28% QoC improvements.
